Surgical decompression can be achieved by opening the abdominal wall and abdominal fascia anterior in order to physically create more space for the abdominal viscera. Once opened, the fascia can be bridged for support and to prevent loss of domain by a variety of medical devices (Bogota bag, artificial bur, and vacuum devices using negative pressure wound therapy ).

Abdominal compartment syndrome occurs when the abdomen becomes subject to increased pressure. Specific cause of abdominal compartment syndrome is not known, although some causes can be sepsis and severe abdominal trauma. Increasing pressure reduces blood flow to abdominal organs and impairs pulmonary, cardiovascular, renal, and gastro-intestinal (GI) function, causing multiple organ dysfunction syndrome and death.

Nutcracker syndrome can be diagnosed with:

- Left renal venography—considered to be the gold standard test.

- Computed tomography (CT).

- Abdominal ultrasonography—not definitive but has been found to be useful.

Median arcuate ligament syndrome is a diagnosis of exclusion. That is, the diagnosis of MALS is generally considered only after patients have undergone an extensive evaluation of their gastrointestinal tract including upper endoscopy, colonoscopy, and evaluation for gallbladder disease and gastroesophageal reflux disease (GERD).

The diagnosis of MALS relies on a combination of clinical features and findings on medical imaging. Clinical features include those signs and symptoms mentioned above; classically, MALS involves a triad of abdominal pain after eating, weight loss, and an abdominal bruit, although the classic triad is found in only a minority of individuals that carry a MALS diagnosis.

Diagnostic imaging for MALS is divided into screening and confirmatory tests. A reasonable screening test for patients with suspected MALS is duplex ultrasonography to measure blood flow through the celiac artery. Peak systolic velocities greater than 200 cm/s are suggestive of celiac artery stenosis associated with MALS.

Further evaluation and confirmation can be obtained via angiography to investigate the anatomy of the celiac artery. Historically, conventional angiography was used, although this has been largely replaced by less invasive techniques such as computed tomography (CT) and magnetic resonance (MR) angiography. Because it provides better visualization of intraabdominal structures, CT angiography is preferred to MR angiography in this setting. The findings of focal narrowing of the proximal celiac artery with poststenotic dilatation, indentation on the superior aspect of the celiac artery, and a hook-shaped contour of the celiac artery support a diagnosis of MALS. These imaging features are exaggerated on expiration, even in normal asymptomatic individuals without the syndrome.

Proximal celiac artery stenosis with poststenotic dilatation can be seen in other conditions affecting the celiac artery. The hook-shaped contour of the celiac artery is characteristic of the anatomy in MALS and helps distinguish it from other causes of celiac artery stenosis such as atherosclerosis. This hooked contour is not entirely specific for MALS however, given that 10-24% of normal asymptomatic individuals have this anatomy.

Diagnosis is very difficult, and usually one of exclusion. SMA syndrome is thus considered only after patients have undergone an extensive evaluation of their gastrointestinal tract including upper endoscopy, and evaluation for various malabsorptive, ulcerative and inflammatory instestinal conditions with a higher diagnostic frequency. Diagnosis may follow x-ray examination revealing duodenal dilation followed by abrupt constriction proximal to the overlying SMA, as well as a delay in transit of four to six hours through the gastroduodenal region. Standard diagnostic exams include abdominal and pelvic computed tomography (CT) scan with oral and IV contrast, upper gastrointestinal series (UGI), and, for equivocal cases, hypotonic duodenography. In addition, vascular imaging studies such as ultrasound and contrast angiography may be used to indicate increased bloodflow velocity through the SMA or a narrowed SMA angle.

Despite multiple case reports, there has been controversy surrounding the diagnosis and even the existence of SMA syndrome since symptoms do not always correlate well with radiologic findings, and may not always improve following surgical correction. However, the reason for the persistence of gastrointestinal symptoms even after surgical correction in some cases has been traced to the remaining prominence of reversed peristalsis in contrast to direct peristalsis.

Since females between the ages of 10 and 30 are most frequently afflicted, it is not uncommon for physicians to initially and incorrectly assume that emaciation is a choice of the patient instead of a consequence of SMA syndrome. Patients in the earlier stages of SMA syndrome often remain unaware that they are ill until substantial damage to their health is done, since they may attempt to adapt to the condition by gradually decreasing their food intake or naturally gravitating toward a lighter and more digestible diet.

The main diagnostic tools are blood tests, X-rays of the abdomen, CT scanning, and/or ultrasound. If a mass is identified, biopsy may determine the nature of the mass.

Radiological signs of bowel obstruction include bowel distension and the presence of multiple (more than six) gas-fluid levels on supine and erect abdominal radiographs.

Contrast enema or small bowel series or CT scan can be used to define the level of obstruction, whether the obstruction is partial or complete, and to help define the cause of the obstruction.

According to a meta-analysis of prospective studies by the Cochrane Collaboration, the appearance of water-soluble contrast in the cecum on an abdominal radiograph within 24 hours of oral administration predicts resolution of an adhesive small bowel obstruction with a pooled sensitivity of 97% and specificity of 96%.

Colonoscopy, small bowel investigation with ingested camera or push endoscopy, and laparoscopy are other diagnostic options.

Fetal and neonatal bowel obstructions are often caused by an intestinal atresia, where there is a narrowing or absence of a part of the intestine. These atresias are often discovered before birth via an ultrasound, and treated with using laparotomy after birth. If the area affected is small, then the surgeon may be able to remove the damaged portion and join the intestine back together. In instances where the narrowing is longer, or the area is damaged and cannot be used for a period of time, a temporary stoma may be placed.

Treatment depends on the severity and symptoms. Treatments include:

- Endovascular stenting.

- Renal vein re-implantation.

- Gonadal vein embolization.

Compartment syndrome is a clinical diagnosis made by a physician. It can be tested for by gauging the pressure within the muscle compartments. If the pressure is sufficiently high, a fasciotomy will be required to relieve the pressure. Various recommendations of the intracompartmental pressure are used with some sources quoting >30 mmHg as an indication for fasciotomy while others suggest a <30 mmHg difference between intracompartmental pressure and diastolic blood pressure. This latter measure may be more sensible in the light of recent advances in permissive hypotension, which allow patients to be kept hypotensive in resuscitation. It is now relatively easy to measure compartment and subcutaneous pressures using the pressure transducer modules (with a simple intravenous catheter and needle) that are attached to most modern anaesthetic machines.

Most commonly compartment syndrome is diagnosed through a diagnosis of its underlying cause and not the condition itself. According to Blackman one of the tools to diagnose compartment syndrome is X-ray to show a tibia/fibula fracture, which when combined with numbness of the extremities is enough to confirm the presence of compartment syndrome.

There are few studies of the long-term outcomes of patients treated for MALS. According to Duncan, the largest and more relevant late outcomes data come from a study of 51 patients who underwent open surgical treatment for MALS, 44 of whom were available for long-term follow-up at an average of nine years following therapy. The investigators reported that among patients who underwent celiac artery decompression and revascularization, 75% remained asymptomatic at follow-up. In this study, predictors of favorable outcome included:

- Age from 40 to 60 years

- Lack of psychiatric condition or alcohol use

- Abdominal pain that was worse after meals

- Weight loss greater than 20 lb (9.1 kg)

Delay in the diagnosis of SMA syndrome can result in fatal catabolysis (advanced malnutrition), dehydration, electrolyte abnormalities, hypokalemia, acute gastric rupture or intestinal perforation (from prolonged mesenteric ischemia), gastric distention, spontaneous upper gastrointestinal bleeding, hypovolemic shock, and aspiration pneumonia.

A 1-in-3 mortality rate for Superior Mesenteric Artery syndrome has been quoted by a small number of sources. However, after extensive research, original data establishing this mortality rate has not been found, indicating that the number is likely to be unreliable. While research establishing an official mortality rate may not exist, two recent studies of SMA syndrome patients, one published in 2006 looking at 22 cases and one in 2012 looking at 80 cases, show mortality rates of 0% and 6.3%, respectively. According to the doctors in one of these studies, the expected outcome for SMA syndrome treatment is generally considered to be excellent.

In medicine, Valentino's syndrome is pain presenting in the right lower quadrant of the abdomen caused by a duodenal ulcer with perforation through the retroperitoneum.

It is named after Rudolph Valentino who presented with right lower quadrant pain which turned out to be perforated peptic ulcer. He subsequently died from an infection inspite of surgery to repair the perforation. The pain is caused by gastric and duodenal fluids that tend to settle in the right paracolic gutter causing peritonitis and RLQ pain.

Patients with perforated Valentino's syndrome usually present with a sudden onset of severe, sharp abdominal pain which is reminiscent of appendicitis. Most patients describe generalized pain; a few present with severe epigastric pain. As even slight movement can tremendously worsen their pain, these patients assume a fetal position. Abdominal examination usually discloses generalized tenderness, rebound tenderness, guarding, and rigidity. However, the degree of peritoneal findings is strongly influenced by a number of factors, including the size of perforation, amount of bacterial and gastric contents contaminating the abdominal cavity, time between perforation and presentation, and spontaneous sealing of perforation.

These patients may also demonstrate signs and symptoms of septic shock, such as tachycardia, hypotension, and anuria. Not surprisingly, these indicators of shock may be absent in elderly or immunocompromised patients or in those with diabetes. Patients should be asked if retching and vomiting occurred before the onset of pain.

The occurrence (incidence) on abdominal or chest X-rays is around 0.1% but it can be up to 1% in series of older adults. It has also been reported in children.

In order to treat acute limb ischaemia there are a series of things that can be done to determine where the occlusion is located, the severity, and what the cause was. To find out where the occlusion is located one of the things that can be done is simply a pulse examination to see where the heart rate can be detected and where it stops being sensed. Also there is a lower body temperature below the occlusion as well as paleness. A Doppler evaluation is used to show the extent and severity of the ischaemia by showing flow in smaller arteries. Other diagnostical tools are duplex ultrasonography, computed tomography angiography (CTA), and magnetic resonance angiography (MRA). The CTA and MRA are used most often because the duplex ultrasonography although non-invasive is not precise in planning revascularization. CTA uses radiation and may not pick up on vessels for revascularization that are distal to the occlusion, but it is much quicker than MRA. In treating acute limb ischaemia time is everything.

In the worst cases acute limb ischaemia progresses to critical limb ischaemia, and results in death or limb loss. Early detection and steps towards fixing the problem with limb-sparing techniques can salvage the limb. Compartment syndrome can occur because of acute limb ischaemia because of the biotoxins that accumulate distal to the occlusion resulting in edema.

The natural history of SCLS episodes indicates they resolve spontaneously within 2-to-4 days, and that they consist of two distinct phases:

SCLS is often difficult to recognize and diagnose on initial presentation, and thus misdiagnoses are frequent. The characteristic triad of profound arterial hypotension, hemoconcentration (elevated hematocrit, leukocytosis, and thrombocytosis), and hypoalbuminemia in the absence of secondary causes of shock and infection, requires diagnosis in a monitored, hospital setting during or after an acute episode. The fact that the condition is exceedingly rare – an estimated one per million inhabitants – and that several other diseases exhibit features akin to SCLS, including secondary capillary-leak syndrome or hypoproteinemia, militate against early identification. Preserved consciousness, despite severe shock and hypotension, is an additional and most intriguing clinical manifestation often reported during episodes at hospital admission.

Acute compartment syndrome is a medical emergency requiring immediate surgical treatment, known as a fasciotomy, to allow the pressure to return to normal. Although only one compartment is affected, fasciotomy is done to release all compartments. For instance, if only the deep posterior compartment of a leg is affected, the treatment would be fasciotomy (with medial and lateral incisions) to release all compartments of the leg in question, namely the anterior, lateral, superficial posterior and deep posterior.

An acute compartment syndrome has some distinct features such as swelling of the compartment due to inflammation and venous occlusion. Decompression of the nerve traversing the compartment might alleviate the symptoms (Rorabeck, 1984). Until definitive fasciotomy can be performed, the extremity should be placed at the level of the heart. Hypotension should also be avoided, as this decreases perfusion pressure to the compartment. Supplemental oxygen also optimizes tissue and neural oxygenation.

Synonyms include interpositio hepatodiaphragmatica, subphrenic displacement of the colon, subphrenic interposition syndrome and pseudopneumoperitoneum.

Zollinger–Ellison syndrome may be suspected when the above symptoms prove resistant to treatment, when the symptoms are especially suggestive of the syndrome, or when endoscopy is suggestive. The diagnosis is made through several laboratory tests and imaging studies:

- Secretin stimulation test, which measures evoked gastrin levels

- Fasting gastrin levels on at least three separate occasions

- Gastric acid secretion and pH (normal basal gastric acid secretion is less than 10 mEq/hour; in Zollinger–Ellison patients, it is usually more than 15 mEq/hour)

- An increased level of chromogranin A is a common marker of neuroendocrine tumors.

In addition, the source of the increased gastrin production must be determined using MRI or somatostatin receptor scintigraphy.

An omphalocele is often detected through AFP screening or a detailed fetal ultrasound. Genetic counseling and genetic testing such as amniocentesis are usually offered during the pregnancy.

As mentioned, permissive hypotension is unwise. Especially if the crushing weight is on the patient more than 4 hours, but often if it persists more than one hour, careful fluid overload is wise, as well as the administration of intravenous sodium bicarbonate. The San Francisco emergency services protocol calls for a basic adult dose of a 2 L bolus of normal saline followed by 500 ml/h, limited for "pediatric patients and patients with history of cardiac or renal dysfunction."

If the patient cannot be fluid loaded, this may be an indication for a tourniquet to be applied.

A compartment syndrome is an increased pressure within a muscular compartment that compromises the circulation to the muscles.

Once ACNES is considered based on the patient's history, the diagnosis can be made via a thorough physical examination: looking for a painful spot, which worsens by tensing the abdominal muscles with lifting the head and straightened legs (Carnett's sign). Almost always, a small area of maximal pain is covered by a larger area of altered skin sensibility with somatosensory disturbances such as hypoesthesia as well as hyperesthesia or hyperalgesia and change of cool perception. Pinching the skin between thumb and index finger is extremely painful compared to the opposite non-involved side.

Confirmation of a diagnosis of ACNES is warranted using an abdominal wall infiltration with a local anesthetic agent near the painful spot.

Another type of thrombolysis disrupts the clot mechanically using either saline jets or, more recently, ultrasound waves. Saline jets dislodge the clot using the Bernoulli effect. Ultrasound waves, emitted at low frequency, create a physical fragmentation of the thrombus.

The diagnosis of retroperitoneal fibrosis cannot be made on the basis of results of laboratory studies. CT is the best diagnostic modality: a confluent mass surrounding the aorta can be seen on a CT scan. Although biopsy is not usually recommended, it is appropriate when malignancy or infection is suspected. Biopsy should also be done if the location of fibrosis is atypical or if there is an inadequate response to initial treatment.